The present invention relates to a machine for processing bicycle frame's downtube automatically.
The downtube of a bicycle frame must be processed through different processing processed by different workers to form drill holes in the middle, a downwards bevel and an inwardly curved top edge on the left end, and a bevel edge of the right end (see FIGS. 1 and 2) the processing processes, the downtube must be firmly retained in position or the processing process will not be accurately performed. Because these processing processes require much time and many workers to complete, the manufacturing cost of the downtube cannot be reduced.
The present invention has been accomplished under the aforesaid circumstances. Therefore, the present invention provides a processing machine which processes the downtube automatically by means of the operation of a drill unit to drill holes on a downtube, a first cutting unit to cut the right end of the downtube by punching, a second cutting unit for to cut a downwards bevel edge on the left end of the downtube by punching, a third cutting unit to cut an inwardly curved top edge on the left end of the downtube by punching, a first locating unit to move the downtube to the processing position for processing, a second locating unit to hold down the downtube in the processing position, and a control circuit control the operation of the aforesaid units in proper order.